Sullivan is a male rat and one of the Rats of NIMH.


Sullivan is mentioned briefly in flashback in Mrs. Frisby and the Rats of NIMH, in which he is denoted as having an engineering bent and being a friend of Arthur.

Sullivan is not mentioned and does not appear in Racso and the Rats of NIMH.

Depiction in filmEdit

Sullivan appeared as a character in The Secret of NIMH, in which he is depicted as a portly gray rat somewhat shorter than Jenner or Justin. In the film he is depicted as Jenner's reluctant accomplice, lacking the maliciousness of the larger rat. He is aware of Jenner's plan to murder Nicodemus and make it look like an accident, which is meant to facilitate Jenner's takeover of the rats. While he does not inform anyone of this treachery, he refuses to aid Jenner in it and attempts to dissuade him. He is later mortally wounded by Jenner for his disobedience, but uses the last of his strength to return the favor by throwing a knife into Jenner's back.